Process of electric welding



May 6 1924.

1.492.991 L. s. LACHMAN PROCESS or ELECTRIC WELDING Filed Feb. 18. 4922 ATTORNEYS Patented May 6, 1924.

UNITED STATES PATENT OFFICE.

LA URENCE S. LACHMAN, OF NEW YORK. N. Y A SSIGNOR TO UNIVERSAL ELECTRIC WELDING COMPANY. OF LONG ISLAND CITY. NEW YORK. A CORPORATION OF NEW YORK.

PROCESS 013 ELECTRIC WELDING.

Application filed February 18, 1922. Serial No. 537,375.

To all whom it may concern:

Be it known that I, LAURENCE S. Leon- MAN, a citizen of the United States, and a resident of New York in the county of New York and State of New York, have-in vented certain new and useful Improve ments in Processes of Electric Welding, of which the following is a specification.

My invention relates to rocesses of electric welding employed Er welding two pieces or plates of metal together at their opposed surfaces by the use of heatin cur rent and pressure applied in' line Wifil the weld in a manner to unite them by what is ordinarily termed a spot weld.

The invention is particularly applicable to the welding of heavy steel oriron plates to 'ether by spot welds.

'2 11 one of the methods as heretofore conducted it has been'proposed to interpose a welding piece between the back surface of the plate or plates and the current sup 1ying and pressure applying electrode an of a size commensurate with-the welded spot, a said welding piece or button, as it is some times called, ci gfalso usually of iron or steel or of material similar to that of the pieces to be welded so that it becomes incorporated in the finished work as an essential part-thereof.

It has also been proposed to unite plates of metal by the use of-anelectrode of copper or other good conducting material the end of which that engages the back surfaces of the work being pointed or of restricted area predetermined y the size of the welded spot that it is desired to produce. a

In the latter method as ordinarily conducted the electrode becomes worn away after one or more operations thus changing the area of contact thereof with the work and so damaging the contacting end as to make it necessary to replace said electrode.

- Furthermore,- the electrode itself being of com aratively soft metal although of good condiicting uality, may be deformed at its contact end y the heavy welding pressure and so that the end wil mushroom or become upset. This is particularly the case when t e attempt -is made to weld thick lates or heavy stock, since with thick plates it is necessary to use very heavy ressurc and a larger current than is required for thinner work. Hence a practical limit is soon reached in the thickness of work that may be commercially and successfully spot welded by what is termed the electrode process.

The special object of my invention is to make it feasible to dispense with the use of a pointed electrode and to weld-very heavy work without damage to the electrode and without the use of welding buttons or pieces which are of a character'to become softened and incor orated with or welded into the work itsel To these'ends my invention consists in a novel method of spot weldin consisting'in first applying to the back 0 the work, as for instance a sheetto be spot welded by its surface to an opposite member; a buttonor piece of good conducting material .such for instance as copper and of a size and in a location predetermined by the size and location of the spot weld which it is desired to reduce and then a plying to the button an work, assembled between the working dies, current and pressure by means of an electrode havin a working face of larger area than said utton to effect a welding of the inner surface of the plate or member to the surface of the opposite member.

In this operation it will be seen that the size and location of the spot weld is rimarily determined by the size of the piece or button of good conducting material and the locating of it on the back surface of the plate rior to the actual welding operation and tii working face for engaging the button of any desired area or preferab y of larger area than the button, instead of being pointed or reduced to a size approximatin that of the weld and that it may be use indefinitely without renewal, the only expense being a supply of the small pieces of cop er in quantity and of size required and o comparatively small value as compared with the electrode itself. The lar e expense of renewal of the usual poin electrode 15 thus avoided.

As willbe seen, in this operation it is not necessary to apply the electrode roper with exactness or special care centre y over the welded spot, the location of the spot be ing chosen by applying the button itself atat the electrode itself may have a the proper point. and serving itself. in tinactual welding operation. as the p inl of the electrode-Whichgrin -lm-tletmche l from the Work-anti clisbarrledafier the work is completed.

Preferably I use a heavy bloc-l: or elm, triod'e o'f mnclrlarger mass or ernss-Suitimml area than the'hutton or piece itself, Slllvr said elect-rode in that case aids in keepin down the temperature of the welding hurimi and prevents softening thereof bytlie'hea l in current or reflect, therehy preserving ii throug'hout the 'proqessns -a neiiinm 'for the application or =trnnsferenee of th'every heavy Said =bnttoii bing;as already stated, (Sf-11 strieted size predetermined hy the eize'of'the epdt weld to 'be produced =anjcl heing there "fore-Imore lieble'toflefornmtion hy the'zrp :plied'pressure.

For the ui pose-of-expiaining my inven "tion it;wi "e-n ssn'megl'that. the proeess =is =eond ieted'in =the-bpersltion of welding 1 two "liblwy platesmf 'ifon-wmdeteel together in their opposed surfaces.

:In"*t e 'aeeompanyin "ehownfin'side elyati on in Fig. mafia-"to. wrhinh ii he invention .plilerf-imd comprising two" 'sfleel 1,':1'to be:-spot 'iyelded together on their 't'op '.-em1faeee.=" i 32+ ii. sction*of'=thefinished monk. mtlcvtesjthe velding piece or pieces eom josed'of-gopd 'oon'dnct'mg material such, fon-mstzrnee'rasflm :rp'ebetiel' of which the "GIQBtIOd-BS 8 'alje composegifto wit: copper. Sairi weldinfi iepeis'of a size qr' arewpredetenfiined vrt'he size or =a1ea ,oftlie'spot which at is" desired to 'prod'u 0e and thereby act-sin effect 11s the contact. enflor point. 'for the maimeleetrogie-fib which it/is engagefl- I The membefs to he wld ecllnn in been nrrnngel in the proper rel'a-five ioiti'on. -tho qveldlnk piece-is applied-to Wire-hack of one of themed: the loch .i'on'df'the spot o'f n'el'rlin -to 'he'prjotlneed. a'ft-evwhieh said parts, with the 'hnttmi $0 'locatetl, =m'e :looate'rl in -assembled'lposi tion placed belni'een the (lies =3 3 and=suhjeetedto'aheating eiirrent and re-by rmefln s'thereo fg the butt-on then.

adtmg this 5th .01 themperation practirnlly a's the .point, of the-n'min electrode -to lo'ealize he welt].

"withiheavy' work piessin-e 'isapplied in drawings I have 1 'thecla'ss of rony 'be "apto-siiik into the'back surface of the plan or -'-plnms"t-hereby applying efi'eetiv wielding pressure while at'the seine time thehnaterial 'of the iece being-6f high conrlnctiviti seffeo tively oealizes the heating ('III'IPIIlZ hll' 'Sflid eenmeimem porated therenith'and 'mav he removed nfter thewovl: is finished.

lin the operation the large masqwf the *eleeisrode'lidck of the =pieceseriesto eonclnet plntesmf iron on linheal :awar therefrom :lllfl maintain it at. .ia|iir-ir-n1.l l w temperature to permit it to iransfer the prmsure efl'eetively. The result of the operation where the piece is 'hnt parliflll V imht-ilderl although the weld is completed is illustrated in the erosssection Fig. 2.

Tn ihis method it will he seen that the pressure fllltl-llfiilii'llg localizing meniber of the :ipparains is the rontacting button or piece which. inasmuch as it, does not become im m-pomterl as apart of the work. serves wall) as the contacting end of the'e'leetrode proper heing made of good conducting material like iaitl eleetrotle nnrl "'o'f'size only SHClL' {iS'n'onlrl l)e= emplore'tl 'for-t-he orcllrtary pointed electrode l'lFCl'l in electrode spot welding. V

I am Mr-are that it. has-'heen before jproposetl'to intr'p'ose a separatejlate'ot g'oe conduct-in; material lilre'eopper between the electrode a'n'dth'e work'to avoid pitting of the eleetrode,'as' for instance iiirol1er semn 'weldih and -injother 'dases 'where e "ep'ot wel'd e eon-ode is need, but, 'in alI'previons said interinstancesof which I emawere pressure localizing meanber 'of' the'mipperat-'11s. Vi'lier-sueh'intei'posed' piece of copper has been empl oyec'tiin eonnectibmwithmn electrocle *it ha'ssenvd meieljnbweonfluet current" n'hi le the lomlizatfon" of rheat aild. ressure' is determined by' theisizw'df the s'upfsree' of' the eleetrode'*-badk of smell" piece and ma-kirrg contact-therewith. What I -eleim=e my' iirwentrion is 1. The herein tle-cribed' '=s ot. melding :t-wo plates orxbheets of metal in their opposed surfedes'eonsisting-in leeeti'ngupon the b11031 of thework a-heat-end ressnre localizing piece of'highei tivity than the work and o 'f a' sikemin'edfbj' the size of the =apot 'we cl to he produced =asseinl'iling the pletes or sheets with the located button =hebween melding dies and *ap'plyingil'ienting current-and pres sure snflicient "to sink Reid pieee in' the sinface "of-the work andefiedt a weld without incorporatingwhe same *iir-the'zfiirishefl work. 2. The herein described improvement in spot welding term-plates oi'metel together =c'onsistingin locatingm' on theabacksn of the Work a heaven looallefii i'eee of metal of 'a 'size predetermm' h the size of =the weld "'tobe produ and in I the position over the welding spot, and of 'a' conductivity :greater than that. 'of the work and then epp'lymg an electrode of larger, mess and working snr-fn'ee mm than the ieee -and eflect-in 'a we'lrl 'in a meeting snn ace of-the plates 3' our-rent and 'pressure applied through said electrode and loea lizing' pieoe, said pressure being made snflieient, to srnk the "piece in the surfaeeoi the evork and eonduered'et'ercad 12B effect a weld between the pieces without welding or incorporating said piece with the work.

The herein described method of spot welding two plates or pieces of iron or steel together consisting in a plying to the back of a plate a heating an pressure localizing piece of good conducting material like copper and of a size and in a location corresponding to the size and location of the spot weld to be produced and then applying to the plates and localizing piece assembled together, welding dies or blocks of any desired size and of heat conducting capacity adapted to prevent fusion of the applied copper piece and effecting the weld of the iron or steel by the application of heating current and pressure through said dies and without causing said piece to become incorporated with the Work.

4. The herein described method of spot welding two plates or pieces of iron or steel together, consisting in applying to the back of the work and in position over the spot of welding, a heat and pressure localizing piece of comparatively good conducting material and of a size predetermined by the size of the spot weld. to be produced assembling the work with the piece so applied in position between the electrodes and subjecting the work to pressure and heating current applied through said separate localizing piece and so as to effect the weld without causing said piece to become incorporated with the work.

Signed at New York in the county of New York and State of New York this th day of February A. D. 1922.

LAURENCE S. LACHMAN.

Witnesses:

F. B. TOWNSEND, GEORGE E. BROWN. 

